1.
Drug nomenclature
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Drug nomenclature is the systematic naming of drugs, especially pharmaceutical drugs. Generic names for drugs are nowadays constructed out of affixes and stems that classify the drugs into different categories, a marketed drug might also have a company code or compound code. The chemical names are the names, based on the molecular structure of the drug. There are various systems of nomenclature and thus various chemical names for any one substance. The most important is the IUPAC name, chemical names are typically very long and too complex to be commonly used in referring to a drug. Sometimes, a company that is developing a drug might give the drug a company code, for example, CDP870 is UCB’s company code for Cimzia. Many of these codes, although not all, have prefixes that correspond to the company name, during development, the company will apply for regulatory approval of the drug by the relevant national regulatory agency, and it will apply for a generic name for that country. It will also apply for an International Nonproprietary Name through the World Health Organization, nowadays the national nonproprietary names are usually the same as the INN. The generic names usually indicate via their stems what drug class the drug belongs to, for example, one can tell that aciclovir is an antiviral drug because its name ends in the -vir suffix. Otherwise the 2 names are both given, joined by hyphens or slashes. For example, suspensions combining trimethoprim and sulfamethoxazole are called either trimethoprim/sulfamethoxazole or co-trimoxazole, similarly, co-codamol is codeine-acetaminophen, and co-triamterzide is triamterene-hydrochlorothiazide. The USP ceased maintaining PENs, but the similar co-prefixed BANs are still current, for drugs that make it all the way through development, testing, and regulatory acceptance, the pharmaceutical company then gives the drug a trade name. The term trade name is a term in the pharmaceutical industry for a brand name or trademark name. For example, Lipitor is Pfizers trade name for atorvastatin, a cholesterol-lowering medication, Drug names are often subject to legal regulation, including approval for new drugs and on packaging to establish clear rules about adulterants and fraudulent or misleading labelling. A national formulary is often designated to define drug names for regulatory purposes, unbiased mentions of a drug place the nonproprietary name first and follow it with the trade name in parentheses, if relevant. This pattern is important for the literature, where conflict of interest is disclosed or avoided. The authors reporting on a study are not endorsing any particular brand of drug and they will often state which brand was used, for methodologic validity, but they do so in a way that makes clear the absence of endorsement. For example, the 2015 American Society of Hematology publication policies say, Non-proprietary names should be used and he first letter of the name of a proprietary drug should be capitalized

2.
PubChem
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PubChem is a database of chemical molecules and their activities against biological assays. The system is maintained by the National Center for Biotechnology Information, a component of the National Library of Medicine, PubChem can be accessed for free through a web user interface. Millions of compound structures and descriptive datasets can be downloaded via FTP. PubChem contains substance descriptions and small molecules with fewer than 1000 atoms and 1000 bonds, more than 80 database vendors contribute to the growing PubChem database. PubChem consists of three dynamically growing primary databases, as of 28 January 2016, Compounds,82.6 million entries, contains pure and characterized chemical compounds. Substances,198 million entries, contains also mixtures, extracts, complexes, bioAssay, bioactivity results from 1.1 million high-throughput screening programs with several million values. PubChem contains its own online molecule editor with SMILES/SMARTS and InChI support that allows the import and export of all common chemical file formats to search for structures and fragments. In the text search form the database fields can be searched by adding the name in square brackets to the search term. A numeric range is represented by two separated by a colon. The search terms and field names are case-insensitive, parentheses and the logical operators AND, OR, and NOT can be used. AND is assumed if no operator is used, example,0,5000,50,10 -5,5 PubChem was released in 2004. The American Chemical Society has raised concerns about the publicly supported PubChem database and they have a strong interest in the issue since the Chemical Abstracts Service generates a large percentage of the societys revenue. To advocate their position against the PubChem database, ACS has actively lobbied the US Congress, soon after PubChems creation, the American Chemical Society lobbied U. S. Congress to restrict the operation of PubChem, which they asserted competes with their Chemical Abstracts Service

3.
ChemSpider
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ChemSpider is a database of chemicals. ChemSpider is owned by the Royal Society of Chemistry, the database contains information on more than 50 million molecules from over 500 data sources including, Each chemical is given a unique identifier, which forms part of a corresponding URL. This is an approach to develop an online chemistry database. The search can be used to widen or restrict already found results, structure searching on mobile devices can be done using free apps for iOS and for the Android. The ChemSpider database has been used in combination with text mining as the basis of document markup. The result is a system between chemistry documents and information look-up via ChemSpider into over 150 data sources. ChemSpider was acquired by the Royal Society of Chemistry in May,2009, prior to the acquisition by RSC, ChemSpider was controlled by a private corporation, ChemZoo Inc. The system was first launched in March 2007 in a release form. ChemSpider has expanded the generic support of a database to include support of the Wikipedia chemical structure collection via their WiChempedia implementation. A number of services are available online. SyntheticPages is an interactive database of synthetic chemistry procedures operated by the Royal Society of Chemistry. Users submit synthetic procedures which they have conducted themselves for publication on the site and these procedures may be original works, but they are more often based on literature reactions. Citations to the published procedure are made where appropriate. They are checked by an editor before posting. The pages do not undergo formal peer-review like a journal article. The comments are moderated by scientific editors. The intention is to collect practical experience of how to conduct useful chemical synthesis in the lab, while experimental methods published in an ordinary academic journal are listed formally and concisely, the procedures in ChemSpider SyntheticPages are given with more practical detail. Comments by submitters are included as well, other publications with comparable amounts of detail include Organic Syntheses and Inorganic Syntheses

4.
Chemical formula
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These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulas can fully specify the structure of only the simplest of molecules and chemical substances, the simplest types of chemical formulas are called empirical formulas, which use letters and numbers indicating the numerical proportions of atoms of each type. Molecular formulas indicate the numbers of each type of atom in a molecule. For example, the formula for glucose is CH2O, while its molecular formula is C6H12O6. This is possible if the relevant bonding is easy to show in one dimension, an example is the condensed molecular/chemical formula for ethanol, which is CH3-CH2-OH or CH3CH2OH. For reasons of structural complexity, there is no condensed chemical formula that specifies glucose, chemical formulas may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. A chemical formula identifies each constituent element by its chemical symbol, in empirical formulas, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, as ratios to the key element. For molecular compounds, these numbers can all be expressed as whole numbers. For example, the formula of ethanol may be written C2H6O because the molecules of ethanol all contain two carbon atoms, six hydrogen atoms, and one oxygen atom. Some types of compounds, however, cannot be written with entirely whole-number empirical formulas. An example is boron carbide, whose formula of CBn is a variable non-whole number ratio with n ranging from over 4 to more than 6.5. When the chemical compound of the consists of simple molecules. These types of formulas are known as molecular formulas and condensed formulas. A molecular formula enumerates the number of atoms to reflect those in the molecule, so that the formula for glucose is C6H12O6 rather than the glucose empirical formula. However, except for very simple substances, molecular chemical formulas lack needed structural information, for simple molecules, a condensed formula is a type of chemical formula that may fully imply a correct structural formula. For example, ethanol may be represented by the chemical formula CH3CH2OH

5.
Jmol
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Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D

6.
Simplified molecular-input line-entry system
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The simplified molecular-input line-entry system is a specification in form of a line notation for describing the structure of chemical species using short ASCII strings. SMILES strings can be imported by most molecule editors for conversion back into two-dimensional drawings or three-dimensional models of the molecules, the original SMILES specification was initiated in the 1980s. It has since modified and extended. In 2007, a standard called OpenSMILES was developed in the open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. The Environmental Protection Agency funded the project to develop SMILES. It has since modified and extended by others, most notably by Daylight Chemical Information Systems. In 2007, a standard called OpenSMILES was developed by the Blue Obelisk open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, in July 2006, the IUPAC introduced the InChI as a standard for formula representation. SMILES is generally considered to have the advantage of being slightly more human-readable than InChI, the term SMILES refers to a line notation for encoding molecular structures and specific instances should strictly be called SMILES strings. However, the term SMILES is also used to refer to both a single SMILES string and a number of SMILES strings, the exact meaning is usually apparent from the context. The terms canonical and isomeric can lead to confusion when applied to SMILES. The terms describe different attributes of SMILES strings and are not mutually exclusive, typically, a number of equally valid SMILES strings can be written for a molecule. For example, CCO, OCC and CC all specify the structure of ethanol, algorithms have been developed to generate the same SMILES string for a given molecule, of the many possible strings, these algorithms choose only one of them. This SMILES is unique for each structure, although dependent on the algorithm used to generate it. These algorithms first convert the SMILES to a representation of the molecular structure. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database, there is currently no systematic comparison across commercial software to test if such flaws exist in those packages. SMILES notation allows the specification of configuration at tetrahedral centers, and these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES

7.
International Chemical Identifier
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Initially developed by IUPAC and NIST from 2000 to 2005, the format and algorithms are non-proprietary. The continuing development of the standard has supported since 2010 by the not-for-profit InChI Trust. The current version is 1.04 and was released in September 2011, prior to 1.04, the software was freely available under the open source LGPL license, but it now uses a custom license called IUPAC-InChI Trust License. Not all layers have to be provided, for instance, the layer can be omitted if that type of information is not relevant to the particular application. InChIs can thus be seen as akin to a general and extremely formalized version of IUPAC names and they can express more information than the simpler SMILES notation and differ in that every structure has a unique InChI string, which is important in database applications. Information about the 3-dimensional coordinates of atoms is not represented in InChI, the InChI algorithm converts input structural information into a unique InChI identifier in a three-step process, normalization, canonicalization, and serialization. The InChIKey, sometimes referred to as a hashed InChI, is a fixed length condensed digital representation of the InChI that is not human-understandable. The InChIKey specification was released in September 2007 in order to facilitate web searches for chemical compounds and it should be noted that, unlike the InChI, the InChIKey is not unique, though collisions can be calculated to be very rare, they happen. In January 2009 the final 1.02 version of the InChI software was released and this provided a means to generate so called standard InChI, which does not allow for user selectable options in dealing with the stereochemistry and tautomeric layers of the InChI string. The standard InChIKey is then the hashed version of the standard InChI string, the standard InChI will simplify comparison of InChI strings and keys generated by different groups, and subsequently accessed via diverse sources such as databases and web resources. Every InChI starts with the string InChI= followed by the version number and this is followed by the letter S for standard InChIs. The remaining information is structured as a sequence of layers and sub-layers, the layers and sub-layers are separated by the delimiter / and start with a characteristic prefix letter. The six layers with important sublayers are, Main layer Chemical formula and this is the only sublayer that must occur in every InChI. The atoms in the formula are numbered in sequence, this sublayer describes which atoms are connected by bonds to which other ones. Describes how many hydrogen atoms are connected to each of the other atoms, the condensed,27 character standard InChIKey is a hashed version of the full standard InChI, designed to allow for easy web searches of chemical compounds. Most chemical structures on the Web up to 2007 have been represented as GIF files, the full InChI turned out to be too lengthy for easy searching, and therefore the InChIKey was developed. With all databases currently having below 50 million structures, such duplication appears unlikely at present, a recent study more extensively studies the collision rate finding that the experimental collision rate is in agreement with the theoretical expectations. Example, Morphine has the structure shown on the right, as the InChI cannot be reconstructed from the InChIKey, an InChIKey always needs to be linked to the original InChI to get back to the original structure

8.
United States Adopted Name
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United States Adopted Names are unique nonproprietary names assigned to pharmaceuticals marketed in the United States. Each name is assigned by the USAN Council, which is co-sponsored by the American Medical Association, the United States Pharmacopeial Convention, and the American Pharmacists Association. In addition to drugs, the USAN Council names agents for gene therapy and cell therapy, contact lens polymers, surgical materials, diagnostics, carriers, the USAN Council began in June 1961 after the AMA and the USP jointly formed the AMA-USP Nomenclature Committee. In 1967, a representative from the Food and Drug Administration was appointed to serve on the USAN Council. The AMA Council on Drugs no longer exists as a separate entity, FDA now has a representative on the USAN Council, which has moved away from chemically derived names. Currently, the USAN Council has five members, one from each sponsoring organization, one from the FDA, one member is nominated to the USAN Council annually by each sponsoring organization, the FDA nominates one liaison member annually. The member-at-large is selected by the organizations from a list of candidates proposed by the AMA, APhA. The five nominees to the Council must be approved annually by the board of trustees of the three sponsoring organizations and this distinguishes them from the trademarked names that have been registered for private use. USANs assigned today reflect both present nomenclature practices and older methods used to name drug entities, early drug nomenclature was based on the chemical structure. As newer drugs became more complex and numerous, nonproprietary names based on chemistry became long and difficult to spell, pronounce. Additionally, chemically derived names provided little information to non-chemist health practitioners. Considering the needs of health led to a system in which USANs reflect relationships between new entities and older drugs, and avoid names that might suggest non-existent relationships. Current nomenclature practices involve the adoption of standardized syllables called stems that relate new chemical entities to existing drug families, stems may be prefixes, suffixes, or infixes in the nonproprietary name. Each stem can emphasize a specific chemical structure type, a pharmacologic property, the recommended list of USAN stems is updated regularly to keep pace to accommodate drugs with new chemical and pharmacologic properties. As a general rule, the application for a USAN should be forwarded to the USAN Council after the Investigational New Drug has been approved by the FDA and clinical trials have begun. Many drug manufacturers seeking a USAN are multinational companies with subsidiaries in various parts of the world or contractual agreements with drug firms outside the United States, assigning a USAN and standardizing names internationally can take anywhere from several months to a few years

9.
Organic compound
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An organic compound is virtually any chemical compound that contains carbon, although a consensus definition remains elusive and likely arbitrary. Organic compounds are rare terrestrially, but of importance because all known life is based on organic compounds. The most basic petrochemicals are considered the building blocks of organic chemistry, for historical reasons discussed below, a few types of carbon-containing compounds, such as carbides, carbonates, simple oxides of carbon, and cyanides are considered inorganic. The distinction between organic and inorganic compounds, while useful in organizing the vast subject of chemistry. Organic chemistry is the science concerned with all aspects of organic compounds, Organic synthesis is the methodology of their preparation. The word organic is historical, dating to the 1st century, for many centuries, Western alchemists believed in vitalism. This is the theory that certain compounds could be synthesized only from their classical elements—earth, water, air, vitalism taught that these organic compounds were fundamentally different from the inorganic compounds that could be obtained from the elements by chemical manipulation. Vitalism survived for a while even after the rise of modern atomic theory and it first came under question in 1824, when Friedrich Wöhler synthesized oxalic acid, a compound known to occur only in living organisms, from cyanogen. A more decisive experiment was Wöhlers 1828 synthesis of urea from the inorganic salts potassium cyanate, urea had long been considered an organic compound, as it was known to occur only in the urine of living organisms. Wöhlers experiments were followed by others, in which increasingly complex organic substances were produced from inorganic ones without the involvement of any living organism. Even though vitalism has been discredited, scientific nomenclature retains the distinction between organic and inorganic compounds, still, even the broadest definition requires excluding alloys that contain carbon, including steel. The C-H definition excludes compounds that are considered organic, neither urea nor oxalic acid is organic by this definition, yet they were two key compounds in the vitalism debate. The IUPAC Blue Book on organic nomenclature specifically mentions urea and oxalic acid, other compounds lacking C-H bonds but traditionally considered organic include benzenehexol, mesoxalic acid, and carbon tetrachloride. Mellitic acid, which contains no C-H bonds, is considered an organic substance in Martian soil. The C-H bond-only rule also leads to somewhat arbitrary divisions in sets of carbon-fluorine compounds, for example, CF4 would be considered by this rule to be inorganic, whereas CF3H would be organic. Organic compounds may be classified in a variety of ways, one major distinction is between natural and synthetic compounds. Another distinction, based on the size of organic compounds, distinguishes between small molecules and polymers, natural compounds refer to those that are produced by plants or animals. Many of these are extracted from natural sources because they would be more expensive to produce artificially

10.
Anabolic steroid
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They are anabolic and increase protein within cells, especially in skeletal muscles. The word anabolic, referring to anabolism, comes from the Greek ἀναβολή anabole and they are one of three types of sex hormone agonists, the others being estrogens like estradiol and progestogens like progesterone. Health risks can be produced by long-term use or excessive doses of AAS and these effects include harmful changes in cholesterol levels, acne, high blood pressure, liver damage, and dangerous changes in the structure of the left ventricle of the heart. Conditions pertaining to hormonal imbalances such as gynecomastia and testicular size reduction may also be caused by AAS and their use is referred to as doping and banned by most major sporting bodies. For many years, AAS have been by far the most detected doping substances in IOC-accredited laboratories, in countries where AAS are controlled substances, there is often a black market in which smuggled, clandestinely manufactured or even counterfeit drugs are sold to users. AAS have largely replaced in this setting by synthetic protein hormones that selectively stimulate growth of blood cell precursors. Growth stimulation, AAS can be used by pediatric endocrinologists to treat children with growth failure, however, the availability of synthetic growth hormone, which has fewer side effects, makes this a secondary treatment. Stimulation of appetite and preservation and increase of mass, AAS have been given to people with chronic wasting conditions such as cancer. Induction of male puberty, Androgens are given to many boys distressed about extreme delay of puberty, Testosterone is now nearly the only androgen used for this purpose and has been shown to increase height, weight, and fat-free mass in boys with delayed puberty. Male contraception, in the form of testosterone enanthate, potential for use in the near-future as a safe, reliable, stimulation of lean body mass and prevention of bone loss in elderly men, as some studies indicate. Hormone replacement for men with low levels of testosterone, also effective in improving libido for elderly males, most steroid users are not athletes. Between 1 million and 3 million people are thought to have misused AAS in the United States, another study found that non-medical use of AAS among college students was at or less than 1%. According to a recent survey,78, the same study found that individuals using AAS for non-medical purposes had a higher employment rate and a higher household income than the general population. AAS users tend to be disillusioned by the portrayal of AAS as deadly in the media, according to one study, AAS users also distrust their physicians and in the sample 56% had not disclosed their AAS use to their physicians. A recent study has shown that long term AAS users were more likely to have symptoms of muscle dysmorphia. A recent study in the Journal of Health Psychology showed that many believed that steroids used in moderation were safe. AAS have been used by men and women in different kinds of professional sports to attain a competitive edge or to assist in recovery from injury. These sports include bodybuilding, weightlifting, shot put and other track and field, cycling, baseball, wrestling, mixed martial arts, boxing, football, such use is prohibited by the rules of the governing bodies of most sports

11.
Nandrolone
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Nandrolone, also known as 19-nortestosterone or 19-norandrostenolone, is a synthetic anabolic-androgenic steroid derived from testosterone. The drug itself is inactive due to its lack of a 17α-alkyl group and is not actually employed in medicine. The positive effects of the drug include muscle growth, appetite stimulation and increased red cell production. Clinical studies have shown it to be effective in treating anemia, osteoporosis and some forms of neoplasia including breast cancer, the lack of alkylation on the 17α-carbon drastically reduces the hepatotoxic potential of nandrolone. Erectile dysfunction is attributed to the action of DHN in the penis since dihydrotestosterone is a known sexual modulator. In addition to its activity, unlike many other AAS. It binds to the receptor with approximately 22% of the affinity of progesterone. The progestogenic activity of nandrolone may serve to augment its antigonadotropic effects, Nandrolone has a very high ratio of anabolic to androgenic action. In fact, nandrolone-like AAS like nandrolone itself and trenbolone are said to have among the highest ratio of anabolic to androgenic effect of all AAS. This is attributed to the fact that, whereas testosterone is potentiated via conversion into dihydrotestosterone in androgenic tissues, Nandrolone is metabolized by the enzyme 5α-reductase, among others. Metabolites of nandrolone include 5α-dihydronandrolone, 19-norandrosterone, and 19-noretiocholanolone, Nandrolone is also known chemically as estra-4-en-17β-ol-3-one or 19-norandrost-4-en-17β-ol-3-one. It is the 19-demethylated analogue of testosterone, and for reason, is also known as 19-nortestosterone. A large number of nandrolone esters have been marketed and used clinically, the most commonly used esters are nandrolone decanoate and nandrolone phenylpropionate. Nandrolone is the parent compound of a group of AAS. Notable examples include the non-17α-alkylated trenbolone and the 17α-alkylated ethylestrenol and metribolone, Nandrolone is also the parent compound of a large group of progestins. They are subdivided into two groups, the estranes and the gonanes, initial reaction constituents of 1, 4-dimetalation of the most electron deficient positions of the aromatic ring–in the case of an estrogen, the 1 and 4-positions. Treatment of this product with weak acid, oxalic acid for e. g. leads to the hydrolysis of the ether, producing β. Hydrolysis under more sternuous conditions results in migration/conjugation of the olefin to yield nandrolone, treatment of 4 with decanoic anhydride and pyridine affords nandrolone decanoate

12.
Propionate
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The propionate or propanoate ion is C2H5COO−. A propionic or propanoic compound is a salt or ester of propionic acid. In these compounds, propionate is often written in shorthand, as CH3CH2CO2 or simply EtCO2, propionates should not be confused with propenoates, the ions/salts/esters of propenoic acid. Sodium propionate, NaC2H5CO2 Methyl propionate, Calcium propionate, Ca2 Potassium propionate, KC2H5CO2 Fluticasone propionate, C25H31F3O5S

13.
Ester
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In chemistry, esters are chemical compounds derived from an acid in which at least one –OH group is replaced by an –O–alkyl group. Usually, esters are derived from an acid and an alcohol. Glycerides, which are fatty acid esters of glycerol, are important esters in biology, being one of the classes of lipids. Esters with low weight are commonly used as fragrances and found in essential oils. Phosphoesters form the backbone of DNA molecules, nitrate esters, such as nitroglycerin, are known for their explosive properties, while polyesters are important plastics, with monomers linked by ester moieties. The word ester was coined in 1848 by German chemist Leopold Gmelin, probably as a contraction of the German Essigäther, ester names are derived from the parent alcohol and the parent acid, where the latter may be organic or inorganic. Esters derived from more complex carboxylic acids are, on the hand, more frequently named using the systematic IUPAC name. For example, the ester hexyl octanoate, also known under the trivial name hexyl caprylate, has the formula CH36CO25CH3, the chemical formulas of organic esters usually take the form RCO2R′, where R and R′ are the hydrocarbon parts of the carboxylic acid and the alcohol, respectively. For example, butyl acetate, derived from butanol and acetic acid would be written CH3CO2C4H9, alternative presentations are common including BuOAc and CH3COOC4H9. Cyclic esters are called lactones, regardless of whether they are derived from an organic or an inorganic acid, one example of a lactone is γ-valerolactone. An uncommon class of organic esters are the orthoesters, which have the formula RC3, triethylorthoformate is derived, in terms of its name from orthoformic acid and ethanol. Esters can also be derived from an acid and an alcohol. For example, triphenyl phosphate is the derived from phosphoric acid. Organic carbonates are derived from acid, for example, ethylene carbonate is derived from carbonic acid. So far an alcohol and inorganic acid are linked via oxygen atoms, in corollary, boron features borinic esters, boronic esters, and borates. As oxygen is a group 16 chemical element, sulfur atoms can replace some oxygen atoms in carbon–oxygen–central inorganic atom covalent bonds of an ester, esters contain a carbonyl center, which gives rise to 120 ° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier and their flexibility and low polarity is manifested in their physical properties, they tend to be less rigid and more volatile than the corresponding amides. The pKa of the alpha-hydrogens on esters is around 25, the preference for the Z conformation is influenced by the nature of the substituents and solvent, if present

14.
Bolandiol
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Bolandiol, also known as 19-nor-4-androstenediol, estr-4-en-3β, 17β-diol, or 3β-dihydronandrolone, is an anabolic-androgenic steroid that was never marketed. A dipropionate ester, bolandiol dipropionate, has been marketed, bolandiol is unique among AAS in that it reportedly also possesses estrogenic and progestogenic activity. Bolandiol is on the World Anti-Doping Agencys list of prohibited substances and it is a potential metabolic precursor to nandrolone. However, several studies have concluded that bolandiol does not alter strength, body composition

15.
International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker

16.
Androgen
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This includes the activity of the primary male sex organs and development of male secondary sex characteristics. Androgens were first discovered in 1936, androgens increase in both boys and girls during puberty. Androgens are also the original anabolic steroids and the precursor of all estrogens, the primary and most well-known androgen is testosterone. Dihydrotestosterone and androstenedione are less known generally, but are of importance in male development. DHT in the embryo life causes differentiation of penis, scrotum, later in life DHT contributes to balding, prostate growth and sebaceous gland activity. Although androgens are described as sex hormones, both males and females have them to varying degrees, as is also true of estrogens. They are one of three types of sex hormones, the others being estrogens like estradiol and progestogens like progesterone, the main subset of androgens, known as adrenal androgens, is composed of 19-carbon steroids synthesized in the zona reticularis, the innermost layer of the adrenal cortex. Adrenal androgens function as weak steroids, and the subset includes dehydroepiandrosterone, dehydroepiandrosterone sulfate, androstenedione, besides testosterone, other androgens include, Dehydroepiandrosterone is a steroid hormone produced in the adrenal cortex from cholesterol. It is the precursor of natural estrogens. DHEA is also called dehydroisoandrosterone or dehydroandrosterone, androstenedione is an androgenic steroid produced by the testes, adrenal cortex, and ovaries. While androstenediones are converted metabolically to testosterone and other androgens, they are also the parent structure of estrone, use of androstenedione as an athletic or bodybuilding supplement has been banned by the International Olympic Committee, as well as other sporting organizations. Androstenediol is the steroid metabolite thought to act as the regulator of gonadotropin secretion. It is found in equal amounts in the plasma and urine of both males and females. Dihydrotestosterone is a metabolite of testosterone, and a potent androgen than testosterone in that it binds more strongly to androgen receptors. It is produced in the skin and reproductive tissue, during mammalian development, the gonads are at first capable of becoming either ovaries or testes. In humans, starting at about week 4, the rudiments are present within the intermediate mesoderm adjacent to the developing kidneys. At about week 6, epithelial sex cords develop within the forming testes, in males, certain Y chromosome genes, particularly SRY, control development of the male phenotype, including conversion of the early bipotential gonad into testes. In males, the sex cords fully invade the developing gonads, the mesoderm-derived epithelial cells of the sex cords in developing testes become the Sertoli cells, which will function to support sperm cell formation

17.
Androgen receptor
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The androgen receptor is most closely related to the progesterone receptor, and progestins in higher dosages can block the androgen receptor. The main function of the receptor is as a DNA-binding transcription factor that regulates gene expression, however. Androgen regulated genes are critical for the development and maintenance of the male sexual phenotype, hence, testosterone is responsible primarily for the development of male primary sexual characteristics, whereas dihydrotestosterone is responsible for secondary male characteristics. Androgens cause slow epiphysis, or maturation of the bones, steroid users of teen age may find that their growth had been stunted by androgen and/or estrogen excess. People with too little sex hormones can be short during puberty, via the Androgen receptor, androgens play a key role in the maintenance of male skeletal integrity. The regulation of this integrity by androgen receptor signaling can be attributed to both osteoblasts and osteocytes, the primary mechanism of action for androgen receptors is direct regulation of gene transcription. The androgen receptor dimer binds to a sequence of DNA known as a hormone response element. Androgen receptors interact with proteins in the nucleus, resulting in up- or down-regulation of specific gene transcription. Up-regulation or activation of transcription results in increased synthesis of messenger RNA, one of the known target genes of androgen receptor activation is the insulin-like growth factor I receptor. Thus, changes in levels of proteins in cells is one way that androgen receptors control cell behavior. One function of receptor that is independent of direct binding to its target DNA sequence, is facilitated by recruitment via other DNA-binding proteins. One example is serum response factor, a protein that activates several genes that cause muscle growth, AR acetylation is induced by androgens and determines recruitment into chromatin. The AR acetylation site is a key target of NAD-dependent and TSA-dependent histone deacetylases, more recently, androgen receptors have been shown to have a second mode of action. As has been found for other steroid hormone receptors such as estrogen receptors. Androgen receptors interact with certain signal transduction proteins in the cytoplasm, Androgen binding to cytoplasmic androgen receptors can cause rapid changes in cell function independent of changes in gene transcription, such as changes in ion transport. In humans, the receptor is encoded by the AR gene located on the X chromosome at Xq11-12. The androgen insensitivity syndrome, formerly known as testicular feminization, is caused by a mutation of the receptor gene located on the X chromosome. The androgen receptor seems to affect neuron physiology and is defective in Kennedys disease, in addition, point mutations and trinucleotide repeat polymorphisms has been linked to a number of additional disorders

18.
Agonist
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An agonist is a chemical that binds to a receptor and activates the receptor to produce a biological response. Whereas an agonist causes an action, an antagonist blocks the action of the agonist, receptors can be activated by either endogenous or exogenous agonists, resulting in a biological response. A physiological agonist is a substance that creates the same bodily responses but does not bind to the same receptor, an endogenous agonist for a particular receptor is a compound naturally produced by the body that binds to and activates that receptor. For example, the endogenous agonist for serotonin receptors is serotonin, a superagonist is a compound that is capable of producing a greater maximal response than the endogenous agonist for the target receptor, and thus has an efficacy of more than 100%. Full agonists bind and activate a receptor, producing full efficacy at that receptor, one example of a drug that acts as a full agonist is isoproterenol, which mimics the action of adrenaline at β adrenoreceptors. Another example is morphine, which mimics the actions of endorphins at μ-opioid receptors throughout the nervous system. Partial agonists also bind and activate a receptor, but have only partial efficacy at the receptor relative to a full agonist. Agents like buprenorphine are used to treat opiate dependence for this reason, as they produce milder effects on the receptor with lower dependence. An inverse agonist is an agent that binds to the same receptor binding-site as an agonist for that receptor, inverse agonists exert the opposite pharmacological effect of a receptor agonist, not merely an absence of the agonist effect as seen with antagonist. An example is the inverse agonist rimonabant. A co-agonist works with other co-agonists to produce the desired effect together, NMDA receptor activation requires the binding of both glutamate, glycine and D-serine co-agonists. An irreversible agonist is a type of agonist that binds permanently to a receptor through the formation of covalent bonds, a few of these have been described. A selective agonist is selective for a type of receptor. E. g. buspirone is a selective agonist for serotonin 5-HT1A, terms that describe this phenomenon are functional selectivity, protean agonism, or selective receptor modulators. Potency is the amount of agonist needed to elicit a desired response, the potency of an agonist is inversely related to its EC50 value. The EC50 can be measured for a given agonist by determining the concentration of agonist needed to elicit half of the biological response of the agonist. The EC50 value is useful for comparing the potency of drugs with similar efficacies producing physiologically similar effects, the smaller the EC50 value, the greater the potency of the agonist, the lower the concentration of drug that is required to elicit the maximum biological response. This relationship, termed the index, is defined as the ratio TD50, ED50

19.
Clostebol
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Clostebol, also known as 4-chlorotestosterone, usually as the ester clostebol acetate, is a synthetic anabolic androgenic steroid. Clostebol is the 4-chloro derivative of the hormone testosterone. The chlorination prevents conversion to dihydrotestosterone while also rendering the chemical incapable of conversion to estrogen, clostebol is a weak AAS with potential use as a performance enhancing drug. It is currently banned by the World Anti-Doping Agency, oral Turinabol, combining the chemical structures of clostebol and dianabol, was widely used in the East German state-sponsored doping program. Clostebol acetate ointment has ophthalmological and dermatological use, a related anabolic steroid, methylclostebol, is a common additive in so-called dietary supplements, generally listed in the convoluted form 4-chloro-17α-methyl-androst-4-en-17β-ol-3-one. In 2016, urinalysis resulted in Therese Johaug testing positive for clostebol, in the US, clostebol is listed as a Schedule III substance

20.
Prasterone
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Dehydroepiandrosterone, also known as androstenolone, is an endogenous steroid hormone. However, DHEA also has a variety of biological effects in its own right, binding to an array of nuclear and cell surface receptors. Exogenous dehydroepiandrosterone used as a medication is often called prasterone, in women with adrenal insufficiency and the healthy elderly there is insufficient evidence to support the use of DHEA. DHEA is sometimes used as an androgen in hormone replacement therapy for menopause, a long-lasting ester prodrug of DHEA, prasterone enanthate, is used in combination with estradiol valerate for this indication. DHEA is produced naturally in the body, but the long-term effects of its use are largely unknown. In the short term, several studies have noted few adverse effects, in a study by Chang et al. DHEA was administered at a dose of 200 mg/day for 24 weeks with slight androgenic effects noted, another study utilized a dose up to 400 mg/day for 8 weeks with few adverse events reported. A longer term study followed patients dosed with 50 mg of DHEA for 12 months with the number, another study delivered a dose of 50 mg of DHEA for 10 months with no serious adverse events reported. As a hormone precursor, there have reports of side effects possibly caused by the hormone metabolites of DHEA. It is not known whether DHEA is safe for long-term use, some researchers believe DHEA supplements might actually raise the risk of breast cancer, prostate cancer, heart disease, diabetes, and stroke. DHEA may stimulate tumor growth in types of cancer that are sensitive to hormones, such as types of breast, uterine. DHEA may increase prostate swelling in men with benign prostatic hyperplasia, high doses may cause aggressiveness, irritability, trouble sleeping, and the growth of body or facial hair on women. It also may stop menstruation and lower the levels of HDL, other reported side effects include acne, heart rhythm problems, liver problems, hair loss, and oily skin. It may also alter the bodys regulation of blood sugar, patients on hormone replacement therapy may have more estrogen-related side effects when taking DHEA. This supplement may also interfere with other medicines, and potential interactions between it and drugs and herbs are possible, DHEA is produced from cholesterol through two cytochrome P450 enzymes. Cholesterol is converted to pregnenolone by the enzyme P450 scc, then another enzyme, CYP17A1, converts pregnenolone to 17α-hydroxypregnenolone, regular exercise is known to increase DHEA production in the body. Calorie restriction has also shown to increase DHEA in primates. Some theorize that the increase in endogenous DHEA brought about by calorie restriction is partially responsible for the life expectancy known to be associated with calorie restriction

21.
Prasterone sulfate
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Dehydroepiandrosterone sulfate, also known as prasterone sulfate, is a naturally occurring, endogenous androstane steroid and neurosteroid and the 3β-sulfate ester of dehydroepiandrosterone. As the sodium salt, prasterone sodium sulfate, DHEA-S is used as a drug in Japan in the treatment of insufficient cervical ripening. Dehydroepiandrosterone sulfate is produced by the addition of a group, catalyzed by the sulfotransferase enzymes SULT1A1 and SULT1E1. DHEA sulfate can also be back-converted to DHEA through the action of steroid sulfatase, in the zona reticularis layer of the adrenal cortex, DHEA-sulfate is generated by SULT2A1. This layer of the cortex is thought to be the primary source of serum DHEA-sulfate. DHEA sulfate levels decline as a person ages as the reticularis layer diminishes in size, dehydroepiandrosterone sulfate levels above 1890 micromol/L or 700-800 µg/dL are highly suggestive of adrenal dysfunction because DHEA-S is made by the adrenal glands and also synthesized in brain. The presence of DHEA-S is therefore used to rule out ovarian or testicular origin of excess androgen, the Endocrine Society recommends against the therapeutic use of DHEA sulfate in both healthy women and those with adrenal insufficiency, as its role is not clear from studies performed so far

22.
Quinbolone
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It was developed by Parke-Davis in an attempt to create a viable orally-administered anabolic steroid with little or no liver toxicity. Quinbolone is a derivative of boldenone with an easily removed cyclopentenyl ether group, most orally administered anabolic steroids function by having an alkylated 17α-carbon atom, which prevents first-pass metabolism by the liver. This approach does, however, give the drug a high hepatotoxicity, quinbolone is not 17α-alkylated, instead it has increased oral bioavailability due to its cyclopentenyl ether group. After ingestion, the inactive quinbolone becomes boldenone, quinbolone itself has very few androgenic effects, and most of what it does have are a result of its conversion to boldenone and its metabolites. Its illicit usage in bodybuilding and athletics likewise proved limited, though drug tests are used to detect its metabolites as it remains a banned substance for most competitive sports. Quinbolone can be prepared from testosterone, reaction with 1, 1-dimethoxycyclopentane followed by heating to eliminate methanol gives quinbolone

23.
Testosterone enanthate
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Testosterone enanthate, or testosterone heptanoate, is an androgen and anabolic steroid and a testosterone ester. Along with testosterone cypionate and testosterone propionate, it is one of the most widely used testosterone esters, testosterone enanthate was first introduced in 1952. Administered via intramuscular injection, it is the most widely used form of testosterone in androgen replacement therapy, testosterone enanthate has an elimination half-life of 4.5 days and a mean residence time of 8.5 days when used as a depot intramuscular injection. It requires frequent administration of approximately once per week, and large fluctuations in testosterone levels result with it, with levels initially being elevated and supraphysiological

24.
Testosterone propionate
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Testosterone propionate, or testosterone propanoate, also known as propionyltestosterone, is an androgen and anabolic steroid and a testosterone ester. Testosterone esters were synthesized for the first time in 1936, and were found to have greatly improved potency relative to testosterone, among the esters synthesized, testosterone propionate was the most potent, and for this reason, was selected for further development, subsequently being marketed. Along with testosterone enanthate, testosterone cypionate, and testosterone undecanoate, Testosterone propionate was introduced in 1937 by Schering AG in Germany under the brand name Testoviron. It was the first ester of testosterone to be introduced, and was the form of testosterone used medically before 1960. In the 1950s, longer-acting testosterone esters like testosterone enanthate and testosterone cypionate were introduced and superseded testosterone propionate, although rarely used nowadays due to its short duration, testosterone propionate remains medically available and is still marketed in the United States. Testosterone acetate Testosterone butyrate Testosterone valerate

25.
Testosterone undecanoate
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Testosterone undecanoate, or testosterone undecylate, is an androgen and anabolic steroid and a testosterone ester. Unlike other testosterone esters, testosterone undecanoate is available in oral and intramuscular formulations. As an excipient, benzyl benzoate has been reported as a cause of anaphylaxis in a case in Australia, bayer includes this report in information for health professionals and recommends that physicians should be aware of the potential for serious allergic reactions to preparations of this type. Testosterone undecanoate has a long elimination half-life and mean residence time when given as a depot intramuscular injection. The elimination half-life and mean time of testosterone undecanoate are 2. 5-fold and 4-fold longer than those of testosterone enanthate. Aveed brand testosterone undecanoate was approved for use in the United States by the FDA in 2014 and it is administered at a dosage of 1,000 mg every 12 weeks via intramuscular injection. In addition to parenteral, a formulation of testosterone undecanoate is also available in Europe

Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of …

QV Nandrolone Deca, a form of nandrolone used by athletes.

Nandrolone, with the differences from testosterone highlighted in red. The methyl group in testosterone at the C19 position has been removed, and the C17β position is where esters are attached to nandrolone.